Research: Combinatorics, Group Theory, and Topology

Office Hours with a Geometric Group Theorist

Greg Bell is an author of a chapter of Office Hours with a Geometric Group Theorist, published by Princeton University Press. His chapter deals with asymptotic dimension of groups.

Office Hours with a Geometric Group Theorist brings together leading experts who provide one-on-one instruction on key topics in this exciting and relatively new field of mathematics. It’s like having office hours with your most trusted math professors.

An essential primer for undergraduates making the leap to graduate work, the book begins with free groups — actions of free groups on trees, algorithmic questions about free groups, the ping-pong lemma, and automorphisms of free groups. It goes on to cover several large-scale geometric invariants of groups, including quasi-isometry groups, Dehn functions, Gromov hyperbolicity, and asymptotic dimension. It also delves into important examples of groups, such as Coxeter groups, Thompson’s groups, right-angled Artin groups, lamplighter groups, mapping class groups, and braid groups. The tone is conversational throughout, and the instruction is driven by examples.